= nonnative, planted and a wildland component, commonly "escapes" cultivation
= nonnative, planted, generally not considered a wildland component or invasive
= a North American native, may naturalize outside its native range
Genus: Frangula
    Frangula alnus - glossy buckthorn
    Frangula californica - California buckthorn
    Frangula caroliniana - Carolina buckthorn
    Frangula purshiana - Cascara buckthorn